Data Center Cooling Without AC


If you're building an enterprise data center, there are plenty of tools and guidance for climate control and monitoring. Not so when the data center doubles as a broom closet. For many small businesses, servers share shelf space with spare keyboards, file boxes and paint cans, and cooling things down typically means leaving the closet door open.

Cool components last longer, and cooler systems run faster and operate more efficiently. That's just common sense. So if your server and storage proposals don't always include cooling assets, you might be missing an opportunity to boost margins on an invoice that's otherwise crowded with commodities.

For this article, the CRN Test Center narrowed its choices to a field of self-contained cooling solutions intended for the small business. These can be the mom-and-pop outfits with one or two servers and other networking gear tucked away in the small room where telephone and Internet connections enter the building. If you're like us, you're imagining at least one such room you've seen firsthand.

Fitting nicely into this category is the NetShelter CX Office Enclosure from American Power Conversion. For evaluation, APC sent us the 18U edition; it's also available in 24U and 36U sizes. In essence, the NetShelter CX is a large heat rejection unit. It performs no refrigeration of its own, but instead pumps heat from installed components into the surrounding room via three large (and quiet) internal fans. Think of the NetShelter CX as a 19-inch, four-post equipment rack enclosed within a large insulated computer cabinet. On its wheels, the unit stands 40 inches high (subtract a few inches if wheels are replaced with the included stationary feet). Its Formica top creates a smooth, flat work surface of 44.5-inches-by-29.5 inches that's suitable as a printer/fax station, collating area or general work space.

The front of this handsome unit has two locking doors, which open for service and front-panel inspection of servers and storage arrays. Toward the rear of either side of the NetShelter are panels that pop off for access to the back side of mounted equipment, the rear rack posts, 14-outlet power distribution unit (included), the system fans and the cable access port. Rubber feet on the bottom of each panel prevent chipping when they're put aside for service. A nice touch.

To evaluate the NetShelter's ability to reject system heat, testers installed a 1U server and 1U storage array, which together drew 594 watts, about half of its rated maximum of 1.2kw (4,100 BTU/hr). APC recommends closing off any empty vertical rack space to maximize airflow through equipment and out the back. But since APC didn't send any of its optional blanking plates, testers improvised with cardboard and foam.

The temperature inside the cabinet began at the same temperature as the testing room -- 80 degrees F. That's at the high end for air intake recommended by ASHRAE (www.ashrae.org) in its environmental guidelines for datacom equipment. After about an hour, the temperature inside the box had risen to 92, two degrees warmer than the maximum allowable temperature. However, an hour later it was still at 92, and remained there from Friday afternoon to Monday morning, when testing ended.

The NetShelter also performs well in terms of power consumption. Its three fans consume just 18 watts and make barely a whisper. What's more, the cabinet's noise dampening, rated at 18.5 dB, kept components far quieter than some desktop PCs. But it comes at a price; the NetShelter CX weighs literally half a ton. So reseller beware: With a shipping weight of 1,000 pounds, drop-shipping is recommended. Also recommended is the NetShelter CX, which would look equally attractive in a boardroom, a server room or a showroom. Base list price is $3,850.